Tolperisone is a centrally-acting muscle relaxant that has been used for the symptomatic treatment of spasticity and muscle spasm (Martindale, The Extra Pharmacopoeia, 30th ed., p. 1211). Tolperisone has also been used in the treatment of conditions which include dysmenorrhea, climacteric complaints, lockjaw, and neurolatyrism.
The chemical structure of tolperisone is shown below.
As can be seen by the foregoing structure, tolperisone contains a chiral center (as indicated by the asterisk). Racemic tolperisone is commercially available as the hydrochloride salt and is sold under trade names such as MYDETON®, MYDOCALM®, MIDOCALM® AND MUSCALM®.
The chiral separation of tolperisone into its R(−) and S(+) enantiomers has been described (See, for example, JP-A-53-40779).
Tolperisone has been shown to exhibit membrane-stabilizing effects in the central and peripheral nervous system (Ono, H., et al., J. Pharmacobio. Dynam. 1984, 7, 171-178). Tolperisone and its salts are used for improving not only different symptoms related to spastic paralysis, but also for improving muscle tone which originates from diseases or conditions such as cervical syndrome, inflammation of the joints, and back pain. Recently, the use of tolperisone for treating neuropathic pain and pain associated with various nervous system disorders has also been described (see, for example, U.S. Patent Application No. 2006/0004050).